One block of 2,100 August 22 calls traded on TMUS today

T-Mobile US, Inc. (NYSE:TMUS) has ascended more than 19% this month to its current perch of $19.77, drawing bullish activity to its options pit. During the past two weeks, speculators have bought to open more than 13 calls for every put, according to TMUS' International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) 10-day call/put volume ratio of 13.22. Likewise, the stock's Schaeffer's put/call open interest ratio (SOIR) of 0.52 indicates that call open interest nearly doubles put open interest among options set to expire in three months or less.

So far today, more than 3,850 calls have been exchanged. Most of this activity has taken place at TMUS' August 22 call, where 2,500 contracts -- including a block of 2,100 -- have crossed at a volume-weighted average price (VWAP) of $0.50. Almost all of the contracts have gone off near the ask price, implied volatility is on the rise, and volume exceeds open interest, suggesting that a good chunk of the calls are being bought to open.

Before call buyers can earn a profit, TMUS has to trot north of the breakeven price of $22.50 (strike price plus the VWAP) by Aug. 16, when the option expires. However, if it remains below the 22 strike, call buyers will lose the initial premium paid.

T-Mobile US, Inc. revealed Monday that it will raise the down payment for an Apple Inc. (NASDAQ:AAPL) iPhone 5 by $50 to roughly $150. Meanwhile, analysts continue to eye the NYSE newcomer, with Barclays initiating coverage on the stock with an "equal weight" rating this morning.